Exponential Tail Behavior of Self-Similar Solutions to Smoluchowski's Coagulation Equation

We consider self-similar solutions with finite mass to Smoluchowski's coagulation equation for rate kernels that have homogeneity zero but are possibly singular such as Smoluchowski's original kernel. We prove pointwise exponential decay of these solutions under rather mild assumptions on the kernel. If the support of the kernel is sufficiently large around the diagonal we also prove that lim(x ->infinity) 1/x log (1/f(x)) exists. In addition we prove properties of the prefactor if the kernel is uniformly bounded below.